Abstract:
Salinity and flooding are as two very important factors of soil degradation. They often occur together and can
cause severe damage to plants. However, plant response to environmental stresses may vary with growth stage at
which exposure occurs. A pot study was conducted in 2005-2006 in northern Aq Qala (northern Iran) to study
combine effects of waterlogging and soil salinity at different growth stages on grain yield and some yield components
of two Iranian spring wheat genotypes, i.e. Kouhdasht and Tajan. Two salinity treatments were applied, viz. a nonsaline
(ECe = 3 dS m-1) and saline soil (ECe= 10 dS m-1). The six waterlogging treatments within each set consisted
of: control (no waterlogging), and waterlogging applied at tillering (T); stem elongation (SE); booting (B); grain
filling (GF); and two spells of waterlogging, i.e. at tillering and grain filling stages (T+GF). In this experiment,
waterlogging was imposed by keeping pots in hypoxia conditions by adding water daily (during up to two weeks) to
110% of available water holding capacity. Results reveal that highest reduction in grain yield; thousand grain weight
(TGW) and harvest index (HI) were observed through waterlogging at T+GF for both wheat genotypes. Nonsignificant
changes in grain yield, TGW and HI were observed via waterlogging at B as compared to control.
Kouhdasht showed better performance than Tajan under saline and saline × waterlogged conditions
Machine summary:
A pot study was conducted in 2005-2006 in northern Aq Qala (northern Iran) to study combine effects of waterlogging and soil salinity at different growth stages on grain yield and some yield components of two Iranian spring wheat genotypes, i.
The results of these experiments showed that a combination of salinity and waterlogging caused a higher reduction in such different growth and yield parameters of wheat genotypes as fresh and dry shoot weight and number of tillers per plant (Akhtar et al.
1. Grain Yield Under non-saline soil conditions, waterlogging caused significant reduction in grain yield of both wheat genotypes at all growth stages, except at T (Fig. 1a).
Effect of waterlogging applied at different growth stages on a) grain yield; b) thousand grain weight; c) straw weight; and d) number of tillers per plant of wheat genotypes under non-saline and saline soil conditions; error bars indicate standard deviation 3.
4. Number of Tillers per Plant (NTP) Under non-saline soil conditions, waterlogging treatments did not cause a significant reduction in NTP of both wheat genotypes as compared to control (Fig. 1d).
Number of Spikes per Plant (NSP) Under non-saline soil conditions, waterlogging applied at B stage caused a significant reduction in NSP of both genotypes as compared to control (Fig. 2a).
Harvest Index (HI) Under non-saline soil conditions, waterlogging applied at all growth stages, except T, lead to significant reduction in HI of both wheat genotypes compared to control (Fig. 2d).